Abstract
The thermal expansion at −150°∼900°C and Young’s modulus at −150°∼700°C and the rigidity modulus at room temperature of Fe-Cr alloys containing 0∼59.10%Cr have been measured, and it has been found that the mean linear coefficient of thermal expansion at 0°∼40°C has minimum values of 9.94×10−6 and 10.60×10−6 in the annealed alloys containing 19.90% and 54.10%Cr, respectively, showing a weak Invar property. In the composition range of about Fe-17∼39%Cr alloys show the Elinvar property at relatively low temperatures, and the highest transition temperature of 230°C is found in the alloy containing nearly 25%Cr. The negative minimum value of the temperature coefficient of Young’s modulus at 0°∼40°C is −6.81×10−5 in the alloy containing 19.43%Cr. A negative minimum value of −9.60×10−5 in the temperature coefficient of Young’s modulus at 0°∼40°C is also obtained with Fe-54.10%Cr alloy, indicating the Invar property.
